[SCSI] libosd: OSDv2 auto detection

Auto detect an OSDv2 or OSDv1 target at run time. Note how none
of the OSD API calls change. The tests do not know what device
version it is.

This test now passes against both the IBM-OSD-SIM OSD1 target
as well as OSC's OSD2 target.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Reviewed-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>